Improvement in adjustable pitch x b boards



' 1. NULL. Adjustable Pitch-Boards.

I N0.154,891-. Patented Sept.8,18 74.

Wit asses: Inventor:

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THE GRAPHIC CO.PHDTl7-LITII.39& 41 PARK PLAE,N,Y;

UNITED STATES PATENT QFFIGE.

JOSEPH NOLL, OF POUGHKEEPSIE, NEW YORK.

IMPROVEMENT IN ADJUSTABLE PITCH-BOARDS.

Specification forming part of Letters Patent No. 154,891, datedSeptember 8, 1874 application filed January 10, 1874.

, keepsie, in the county of Dutchess and State of New York, haveinvented a new and Improved Adjustable Pitch-Board, of which thefollowing is a specification:

In the accompanying drawings, Figures 1 and 2 represent front elevations.of my improved pitch-board for carpenters and stair builders, oneshowing it in position when not in use, the other adjusted to the pitchand tread of the staircase ready for use.

Similar letters of reference indicate corresponding parts.

The object of my invention is to furnish for the use of stair-buildersand carpenters an adjustable pitch-board, which may be set to any pitchof step and width of tread, as required, forming thereby a very usefuland labor-saving instrument.

I Stair-builders at present cut a pitch-board of wood for everystair-case. This board frequently gets shrunk or warped, so that thenecessary accuracy is not obtained, and that either a new one isrequired or time lost in correcting the inexact workmanship produced.For the purpose of dispensing with the former and remedying the latterdefects, I have constructed a pitch-' board, which may be made of metal,with slidin g and slatted sides, arranged in such a manner'that thepitch and width of tread may be adjusted along the slatted sides of arectangular corner-piece, and set rigidly, by suitable clamping-screwsand connecting pieces, to be readily used on either side.

In the drawing, A represents the pitch -board, which is preferably madeof iron or other metal, and produced of a rectangular corner-piece, B,side extensions 0, and connecting-pieces D. These pieces are soconnected that a rectangular triangle with adjustable sides is formed,which serves by the extensions 0 for adjusting the pitch of the step andwidth of tread while the pieces D form the hypotenuse of the triangle,and give the necessary stability to the sides. The corner-piece B, aswell as t e sides 0 and pieces D, are provided with s ts a, theextensions 0 sliding in those of corner-piece B, by means of set-screwsb and guide-pin d. The pieces D, which connect the ends of the sideextensions 0, are sl tted and extended in similar manner by pin andset-screw, so as to oorres 0nd in length to that of the sides. Short slts e, at the connecting ends of pieces D, serve, in connection withsetscrews 6 of piec'esO, to bind their ends rigidly together. The slatsa are preferably beveled on one side of the pitch-board, so thatset-screws b may be sunk below the surface of the pieces, and allow theuse of the pitch-board on either side and direction, as required.

When it is desired to adjust it for use, the length of tread is producedby the extension of one piece, (3, along corner-piece B, and the pitchalong the other. The connecting-pieces D are extended at the same timeby following the motions of the sides, and are exactly adjusted to thecorner-edges thereof. The setscrews are then firmly tightened, and thepitch-board is ready for use without being liable to shrinking orwarping, doing also more exact work, and forming a very durable andconvenient instrument for stair-builders.

Having thus described my invention, I claim as new and desire to secureby Letters Patent The adjustable pitch-board for stair-builders andcarpenters, produced of rectangular corner-piece B, extensionslide-pieces G, and connecting hypotenuse-pieces D, all being slattedand adjusted by means of guide-pins and set-screws to the pitch andtread of the steps, substantially in the manner and for the purposesdescribed.

JOSEPH NOLL. Witnesses:

T. B. MOSHER, ALEX; F. Romans.

